Today, vehicles such as cars, boats, and aircrafts move at speeds that expose their occupants to the risk of body injury and death in the event of a collision. Car accidents are a major cause of morbidity and mortality. Annually, about 3 million people are injured, many are permanently disabled and many die as a result of their injuries. Seatbelts and inflatable safety devices (air bags) have undoubtedly saved innumerable lives. However, one issue with airbags is that they are deployed after a collision and not before.
Measures to prevent collisions are far more valuable in saving lives than measures deployed after a crash. Sensors have been utilized to prevent accidents such as using ultrasound, video cameras, lasers and radar. However, signals/alarms emanating from monitoring these sensors are available only to the driver of the vehicle into which they are integrated, and not to drivers of other vehicles. In addition, once a collision has occurred, there is currently no reliable method to immediately discover and report the accident.
Fender benders are the most common type of motor vehicle accidents. Two million or more occur each year, in parking lots, when backing up into oncoming traffic, or when stopping suddenly. Although rarely a cause of serious injuries, fender benders often result in costly repairs and increased in insurance rates. In order to prevent Fender Benders, a variety of technologic advances have been deployed. Recently, forward-collision detection and lane-departure electronic signals warn the driver of the vehicle to take corrective action, usually by a visual and/or audible warning whenever a car strays from its lane or gets too close to the car ahead. Color coding of the closeness to the car ahead helps to alert the driver as to the distance ahead, green, yellow and red. These warnings are often muted at low speeds, such as less than 15 miles per hour. Forward-collision detection and lane-departure detection systems typically rely on radar, ultrasound, or camera imaging.
Tailgating is responsible for more than one third of all motor vehicle accidents. Tailgating is defined as a vehicle encroaching on the safe space between that vehicle and a leading vehicle (the car ahead of you). When tailgating occurs, it is often impossible to stop your vehicle in the event that the leading vehicle decelerates suddenly, resulting in a collision. This “safe” distance varies with several factors such as speed of vehicle, road conditions, darkness (ambient light), and weather conditions. Current sensors are available to estimate this “safe” distance, but the information is only available to the driver of the vehicle on which those sensors are integrated. Safety tips such as maintaining a distance between your vehicle and the leading vehicle (e.g. car ahead of you) often suggest keeping 10 feet of distance for every 10 mile per hour of speed. For instance, 60 feet is deemed a safe distance for speeds of 60 mph. This distance increases during inclement weather. There is also a two second rule between the vehicle and the leading vehicle as each passes a stationary object (e.g. a light post or a road sign). This relies on the driver accurately measuring two seconds between when the leading vehicle passes the stationary object and when the driver's vehicle passes the stationary object. The two second rule applies to dry road conditions, as four seconds is recommended for wet roads, and ten seconds for snow or ice covered roads. Tailgating is not only illegal but also causes serious and fatal accidents.
Drivers of vehicles backing up in a parking lot have difficulty seeing pedestrians or other vehicles in the line of travel. Similarly drivers parking (looking for a parking space) and pedestrians have difficulty seeing cars that are backing out of parking spaces.
Many vehicular accidents are avoidable. Often, a driver of a first vehicle (index vehicle) is following too close behind a second vehicle and, when the second vehicle slows down or stops, the driver of the first vehicle (index vehicle) has insufficient time to stop, thereby resulting in a collision.
Drivers are human, and each driver constantly makes driving decisions based upon speed, road conditions, traffic, etc. It is often recommended that one maintain at least one car length per ten miles per hour, but it is often difficult to determine five or six car lengths, as this is an imaginary distance and based on a fictional car size as imagined by the driver. Other than vehicle velocity, stopping distance is impacted by the road surface, road conditions (e.g. wet, snow, ice), tire conditions, vehicle load, tire condition, tire pressure, brake shoe wear, etc. These factors also apply to self-driving vehicles.
To this, it is difficult for a driver to know what a safe following distance might be given such diverse condition. Yet, driving at a safe distance from other vehicles is critical to avoiding accidents.
There have been some limited attempts to provide a system that projects an image onto the roadway for helping with distance control between vehicles. For example, U.S. Pat. No. 9,221,509 to Lai for a Display Apparatus and Vehicle Having Projector Device has a display projection system for a vehicle that presents data on a roadway surface in front of the vehicle. The shape, size, and/or location of the projected image are not dynamic and do not change based upon vehicle speed, road conditions, steering wheel rotation, etc., and therefore cannot be relied upon to reliably prevent collisions U.S. Pat. Publication 2008/0219014 to Loibi for a Bicycle Bumper with a Light Generating a Bike Lane has a light emitter on a bicycle that emits a pattern indicating to other bikers an unsafe passing area. Again, this is a static pattern that does not change based upon bicycle speed, road conditions, steering direction, etc.
What is needed is a system that will inform drivers of dynamic zones of safe distances between vehicles.